DESCRIPTION (Adapted from the application) This core was established at the time of the last competing renewal. This core will help the investigators with ex vivo maintenance of highly differentiated cells and tissues. The specific aims are to provide: 1.a facility with state-of-the-art expertise and equipment with which to perform sophisticated forms of cell culture; 2. stocks of highly differentiated cell lines; 3. tested reagents such as collagenase and serum tested for efficacy on liver and GI tissues; 4. preparations of extracellular matrix components of tissue extracts enriched in ECM and/or assistance with utilization of commercially available forms of ECM components; 5. consultation and assistance with designs for optimal culture conditions for ex vivo maintenance of differentiated cell types whether primary or for cell lines; 6. serum-free chemically and hormonally defined media tailored for growth or for differentiation of liver or GI tissue-derived cells or for cell lines; 7. freshly isolated cell suspensions from normal or diseased tissues of liver or GI tract; and 8. assistance with sophisticated forms of flow cytometry for isolation of and/or characterization of cells derived from the liver or GI tissue.